Centering and caging mechanism for gyroscopes



w. C. FlLL-saowN CENTER'ING AND CAGING MECHANISM FOR cYRoscoPEs Filed Sept. 15, v1952 Aug. 3, 1954 Patented Aug. 3, 1954 TENT OFFICE vCENTERING AND CAGING MECHANISM FOR GYROSCOPES Application September 15,1952, Serial No. 309,613

Claims. I

The invention relates to gyroscopic devices, such as gyro verticals, artificial horizons, etc, and more particularly to novel mechanism for centering or erecting and caging such devices.

In some gyroscopes used heretofore, the caging mechanism is drivably connected to a manually operable or motor driven actuatin' means by a spring to cushion the caging. When an angular torque is applied to the gimbal as in caging, the rotor casing first rotates about its axis until it engages its limit stops and thereafter the gimbal rotates to centered position. While the rotor casing is rotating to its stops, and before the gimbal begins to move angularly, the spring connecting the caging mechanism and the actuating mechanism stores energy and when the rotor casing reaches its stops, the stored energy in the spring rotates the gimbal violently to centered position.

The main object of the present invention is to provide for smooth caging of the gyroscope and thereby avoid the violent movement of the gimbal described above.

The invention contemplates a centering or erecting or caging mechanism for a gyroscope actuated by driving means operatively connected to the caging mechanism by a slip clutch or other suitable means to provide for smooth caging of the gyroscope and to avoid storing energy in the system and thereby prevent violent movement of the gimbal to centered position.

The foregoing and other objects and advan tages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawing wherein one embodiment of the invention is illustrated. It is to be ex pressly understood, however, that the drawing is for the purposes of illustration and description only, and is not to be construed as defining the limits of the invention.

The single figure of the drawing is a schematic perspective view of a gyroscope having a novel centering or erecting and caging mechanism constructed according to the invention.

Referring now to the drawing for a more detailed description of the novel mechanism of the present invention, the mechanism is shown as applied to a gyro vertical including a rotor i rotatable within a case or support 3 for spinning about a normally vertical axis Z. The rotor case is mounted for oscillation about a horizontal pitch axis Y within a gimbal 5 by trunnions l, 9. The gimbal is mounted for oscillation about a second horizontal r011 axis X perpendicular to axis Y by trunnions II, 13 supported by a housing or frame E5. The gyroscope rotor has three degrees of freedom, and the instrument, when mounted on a craft, has its trunnions H, l3 extending parallel to the longitudinal craft axis and its trunnions l, 9 extending parallel to the transverse craft axis.

The novel caging and centering apparatus of the present invention includes a cam l'i secured to trunnion 9 within gimbal 5 and oscillating with the rotor case about pitch axis Y. A cam 59 is secured to trunnion l3 and oscillates with gimbal 5 about roll axis X. Cams ll and IS have cam faces 2i and 23, respectively. Cam faces 2! and 23 have detents 25 and 2'1, respectively, and gimbal 5 has a slot 29 extending lengthwise thereof between the detents for the purposes described hereinafter.

A support 3| is rigid with a pin 33 pivoted to frame l5 and swings between the unoaging position shown in solid lines and the caging position shown in broken lines. A rod-like cam follower as is mounted on the support and successively engages both cam faces 23, 2! as support 3! pivots to caging position. A slot 31 in frame 5 receives a roller 38 rotatable on one end of cam follower 35 and guides the cam follower and sup-port as it swings about pin 33. As support 3! pivots toward caging position, cam follower 35 engages cam face 23 and exerts a precessing force on the gyroscope which causes rotor case 3 to rotate about the Y axis until cam face 2i engages a stop pin 5i. Cam follower 35 then rides on cam face 23 and rotates gimbal 5 about roll axis X until cam follower 35 is positioned in detent 27, whereupon gimbal 5 is centered. Further pivotal movement of support 31 causes cam follower 35 to enter slot 28 in gimbal 5 and ride on cam face 2| and rotate rotor case 3 about the pitch axis Y until cam follower 35 is positioned in detent 25, whereupon the rotor case is centered about both axes.

Support 31 may be pivoted from the solid line uucaging position to the broken line caging position by a motor 39 rotating a cam A! which engages a cam follower ti on a lever d3 fixed to pin 33. The motor is energized from a three-phase power source it]. A single-pole-double-throw limit switch 45 and a double-pole-double-throw manual switch i! are connected in series with the motor and one phase of the power source and switch 4'! also is connected in series with the motor and a second phase of the power source. Upon closing switch 47, motor 39 is energized and cam 4i pivots lever 43 until support 3| is in cagmotor.

ing position, vrh reopen the lever operates switch and stops motor 32. The gyroscope is uncaged by moving switch 5 to the opposite pole whereupon motor 39 is again energized and rotates earn 5! in the opposite direction and a spring 39, having one end attached to support 31 and its other end attached to frame l5, pivots support 3! to unoaged position. Motor 33 stops when support 35 is in uncaged position and lever 53 releases limit switch 65. The support he pivoted again to caging position by motor 33 when switch 81 is again moved to the opposite pole.

The gyroscope described above corresponds generally to the gyroscope shown and described in applicants earlier Patent No. 2,580,743 issued January 1, 1952, and assigned to the same as signee as the present application. However, in the gyroscope described above, when cam. follower 35 engages cam is, rotor casing 3 pivots about the Y axis until the associated cam ll engages stop pin 51 and, during this time, the gimbal does not rotate about its Either the motor must stall or an excessive force may be exerted on the caging mechanism and cause the mechanism to fail.

As mentioned. above, a spring is sometimes used to drivingly connect the motor and the caging mechanism, but during the time the rotor casing is rotating to its stops, the spring stores energy. The energy stored in the spring is suddenly released when the gimbal begins to rotate and the gimbal is moved violently to centered posit1on.

To overcome these diiiiculties, in the present embodiment of the invention a slip clutch 53 drivingly connects the caging mechanism to the Cam il is drivingly connected to motor 39 by slip clutch 53 which comprises a friction element 55 secured to the cam and in driving engagement with a drum 5? fixed to motor 38. The frictional engagement between element 55 and drum 5? may be varied by adjusting a screw 59. With the novel arrangement described, when the gimbal resists movement of cam follower 35 during rotation of rotor casing 3 to its limit, drum 57 rotates relative to friction element 55 without stalling motor 5%} and Without storing energy in the system. When gimbal E rotates after rotor casing 3 reaches its limit, then motor 39 smoothly drives the gimbal to centered position through the friction clutch.

The caging mechanism described herein has all the advantages of those set forth in applicants earlier patent mentioned above and the invention provides for smooth caging of the gyroscope and avoids excessive force being exerted by the motor on the caging mechanism.

Although but one embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes can be made in the design and arrangement of the parts without department from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

I claim:

1. In a gyroscope having a rotor spinning in a support about one axis and means including a gimbal mounting the support for rotation about ill mutually perpendicular axes other than the spin axis, caging means for positioning the gimbal and the support with the rotor spin axis in a predetermined attitude, driving means for operating said caging means, and means operativeiy con necting said driving means and said caging means including means providing for relative movement of said driving means and said caging means without storing energy therein when movement of said caging means is prevented.

2. In a gyroscope having a rotor spinning in a support about one axis and means including a gimbal mounting the support for rotation about mutually perpendicular axes other than the spin axis, oaging means for positioning the gimbal and the support with the rotor spin axis in a predetermined attitude, driving means for operating said ca-ging means, and means operatively connecting driving means and said caging means and including 2. friction clutch providing for relative mover nt of said means and said caging means without storing energy therein when movement of caging mean is prevented.

Structure as described in claim 2 including means for adiur ing the friction clutch vary the fore transmitted by the driving m to the caging means.

4. A caging and centerin device For a gyroscope comprising in combination with a rotor adapted for spinning in a support about one axis. and means including a ginihal mounting said support for freedom about mutually pe'pen icular axes other than the spin axis, of means including a member rotatable with said gimoal, a second member rotatable with sai support, and an element for en aging both of said memscrs to mo e said gimbal and support to centered position. driving means for moving said element into engagement with said members, and means operatively connecting said driving means and said element and including means providing for relative movement of said driving on and. said element without storing energy thei h when movement of said element is prevented.

5. In a gyroscope having a rotor spinning in a support about one axis and means including a. gimbal mounting the support for rotation a? mutually perpendicular axes other than the cam-like member rote-table v. the go:

engaging said cam e members to giinbal and the support with the re in a predetermined attitude, drivin moving said element into engagement cam-like members, and means operatively connecting said driving means and said element including a friction clutch providing for relative movement of said driving means and said element without storing energy therein.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,441,307 Alkan May 11, 1948 2,507,451 Molnar et al May 9, 1950 2,524,553 Wendt Oct. 3, 1950 2,580,748 Fillehrown Jan. 1, 1952 

